<template>
  <div class="cmt-container">
    <h3>发表评论</h3>
    <hr />
    <textarea placeholder="请输入要评论的内容（最多吐槽120字）" maxlength="120" v-model="msg"></textarea>

    <mt-button type="primary" size="large" @click="postComment">发表评论</mt-button>
    <div class="cmt-list" v-for="(item, i) in comments" :key="i">
      <div class="cmt-item">
        <div
          class="cmt-title"
        >第{{ i+1 }}楼&nbsp;&nbsp;用户：{{ item.user_name }}&nbsp;&nbsp;{{ item.add_time | dateFormat }}</div>
        <div class="cmt-body">{{ item.content === 'undefined' ? '此用户很赖，什么都没说': item.content }}</div>
      </div>
    </div>

    <mt-button type="danger" size="large" plain @click="getMore">加载更多</mt-button>
  </div>
</template>
<script>
import { Toast } from "mint-ui";

export default {
  data() {
    return {
      pageIndex: 1, //默认展示第一页数据
      comments: [], // 所有的评论数
      msg: "" //评论输入的内容
    };
  },
  created() {
    this.getComments();
  },
  methods: {
    getComments() {
      //获取评论
      this.$http
        .get("api/getcomments/" + this.id + "?pageindex=" + this.pageIndex)
        .then(res => {
          if (res.body.status === 0) {
            // this.comments = res.body.message
            // 每当获取新评论数据的时候，不能清空覆盖原有评论数据，应该原有数据加上新数据
            this.comments = this.comments.concat(res.body.message);
          } else {
            Toast("获取评论失败！");
          }
        });
    },
    getMore() {
      this.pageIndex++;
      this.getComments();
    },
    postComment() {
      //校验是否为空内容
      if (this.msg.trim().length === 0) {
        return Toast("评论内容不能为空！");
      }

      //发表评论
      //参数1：请求的URL地址
      //参数2：提交给服务器的数据对象 {content：this.msg}
      //参数3：定义提交时候，表单中数据的格式 {emulateJSON: true}
      this.$http
        .post("api/postcomment/" + this.$route.params.id, {
          content: this.msg.trim()
        })
        .then(res => {
          if (res.body.status === 0) {
            // 1.拼接出一个评论对象
            const cmt = {
              user_name: "匿名用户",
              add_time: Date.now(),
              content: this.msg.trim()
            };
            this.comments.unshift(cmt);
            this.msg = "";
          }
        });
    }
  },
  props: ["id"]
};
</script>
<style lang="scss" scoped>
.cmt-container {
  h3 {
    font-size: 18px;
  }
  textarea {
    font-size: 14px;
    height: 85px;
    margin: 0;
  }

  .cmt-list {
    margin: 5px 0;
    .cmt-item {
      font-size: 13px;
      .cmt-title {
        line-height: 30px;
        background-color: #ccc;
      }
      .cmt-body {
        line-height: 35px;
        text-indent: 2em;
      }
    }
  }
}
</style>
